## Summary of the Pull Request
Add an explicit background color to part of the settings UI to prevent animation overflow. The previous solution (adding a ScrollViewer) caused problems.
## References
#10619 adds a ScrollViewer for one of the issues in #10609
## PR Checklist
* [x] Closes#10664
* [x] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [ ] Tests added/passed
* [ ] Documentation updated. If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/terminal) and link it here: #xxx
* [ ] Schema updated.
* [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx
## Detailed Description of the Pull Request / Additional comments
## Validation Steps Performed
Visually confirmed the animation doesn't overflow, changed the theme and confirmed the colors are responsive. Confirmed the extra scrollbar is gone.